(1) Field of the Invention
The present invention relates to silicon carbide bodies of which resistivity is enhanced.
(2) Related Art Statement
For example, JP-A 10-256,108 and JP-A 01-224,286 describe methods for producing films of silicon carbide on surfaces of substrates such as graphite by the chemical vapor deposition method. Such silicon carbide films tend to exhibit high density and high erosion resistance.
The present inventors have been required to obtain films of silicon carbide having increased electric resistivity and resistance, because there is a demand for the formation of films of highly resistive silicon carbide in the field of semiconductor-producing apparatuses. However, it has been difficult to increase the electric resistivity of films of silicon carbide beyond a certain level even by changing various producing conditions in performing the chemical vapor deposition method, such as the flow rates of a carrier gas, a silicon source gas and a carbon source gas, a film-forming temperature and a film-forming time period in any way.
It is an object of the present invention to provide a dense silicon carbide body which has a high purity and a high relative density and of which electric resistivity is enhanced.
The present invention relates to a silicon carbide body comprising polycrystals of silicon carbide, which silicon carbide body has a purity of silicon carbide of not less than 99.9999 wt %, a relative density of not less than 99% and a ratio of silicon of not less than 70.12 wt %. The purity of the silicon carbide body being not less than 99.9999 wt % means that the total weight of all metallic elements excluding Si and C is less than 0.0001 wt %.
These and other objects, features and advantages of the invention will be appreciated when taken in conjunction with the attached drawings, with the understanding that some modifications, variations and changes of the invention could be made by the skilled person in the art to which the invention pertains.